Asphalt-based roofing materials, such as roofing shingles, roll roofing, and built-up roofing, are installed on the roofs of buildings and residential dwellings to provide protection from the elements. When asphalt is used in roofing applications, the asphalt is first heated in a vessel, such as a gas-fired roofing kettle. As the temperature of the asphalt rises, volatile materials, such as hydrocarbons, sulfides, and mercaptans, are emitted that can have strong, unpleasant, and potentially harmful odors. The odors emitted are not only unpleasant to smell, but they may also be an irritant to workers and/or other individuals in the vicinity of the vessel or to those who come within close range of the hot asphalt. For instance, the odorous fumes from the asphalt may cause headaches and/or irritation to the eyes and mucus membranes of the nose and throat, which can result in a deterioration of worker productivity and/or in increase in the number of sick days taken by workers.
Compositions and odor-masking additives for reducing undesirable odors emitted from odor-causing compounds are known in the art. Non-limiting examples of such compositions and odor-masking additives are set forth below.
U.S. Pat. No. 5,271,767 to Light, Sr., et al. discloses a composition that consists essentially of (1) liquid asphalt, hot-mix asphalt, hot-mix, or cold lay asphalt with added latex and (2) an additive that contains a citrus terpene (4-isopropyl 1-methylcyclohexene) D-limonene mixed with a vegetable oil such as cottonseed oil, soya oil, rapeseed (canola) oil, peanut oil, etc. and a silicone oil dispersant. It is taught that when 0.5-1.0 parts of the composition are mixed with 99.0-99.5 parts liquid asphalt, the resulting liquid asphalt composition is substantially free of objectionable odors.
U.S. Pat. Nos. 5,989,662 and 6,107,373 to Janicki, et al. disclose methods of reducing fumes produced from a kettle of molten asphalt that includes adding about 0.25 to about 6.0% by weight of a polymer (e.g. polypropylene) to the asphalt. The polymer material preferably forms a skim or skin across substantially the entire upper surface of the asphalt. Janicki teaches that at least a 25% reduction of the visual opacity of the fumes, at least a 20% reduction of the hydrocarbon emissions of the fumes, and at least a 15% reduction of suspended particulate emissions of the fumes is obtained.
U.S. Pat. No. 6,461,421 to Ronvak discloses a composition that includes (1) an odor-emitting hydrocarbonaceous material, (2) an odor-suppressing amount of an aldehyde or a ketone, and (3) a carboxylic acid ester. The odor-emitting hydrocarbonaceous material may be any hydrocarbonaceous material that emits objectionable odors at ambient or elevated temperatures. One example of a hydrocarbonaceous material given is asphalt. It is asserted that the composition significantly reduces the odor given off by asphalt.
U.S. Pat. No. 6,488,988 to Trumbore, et al. discloses a method and container for reducing the fuming of asphalt in a heated vessel. Trumbore teaches that a substantially insoluble blanket material is added to the liquid asphalt to form a skim on the surface of the asphalt and reduce the fuming. Examples of blanket materials include polyurethane, polyethylene terephthalate, ground soda bottles, starch, and cellulosic materials.
U.S. Pat. No. 6,987,207 to Ronvak discloses a composition that includes an odor-emitting hydrocarbonaceous material and an odor-suppressing amount of an additive composition that includes (1) a soy methyl ester, (2) at least one aldehyde and/or at least one ketone, and (3) at least one carboxylic acid ester. Ronvak teaches that the odor-emitting hydrocarbonaceous material may be any hydrocarbonaceous material that emits objectionable odors at ambient or elevated temperatures, such as asphalt. It is asserted that the use of the additive composition may significantly reduce or eliminate the odor emitted by the hydrocarbonaceous material.
U.S. Pat. No. 7,037,955 to Timcik and U.S. Patent Publication No. 2006/0155003 to Timcik, et al. disclose methods for reducing odor in an oil based medium such as asphalt. In the disclosed methods, an essential oil is added to the oil based medium in an odor reducing amount. The essential oil may be one or more essential oils or essential oil components, and includes natural extracts of various products of aromatic plants and trees. Essential oils for use in the invention include ajowan, angelica root, angelica seed, aniseed china star, carrot seed, and fir needle, among many others. Examples of essential oil components include terpenes, alcohols, aldehydes, aromatics, phenolics, esters, terpene derivatives, non-terpene essential oil components, and terpene derivatives.
U.S. Patent Publication No. 2005/0223668 to Thompson, et al. discloses a faced fibrous insulation assembly that includes a fibrous blanket, a facing formed by a kraft paper sheet material, and an asphalt coating layer on the inner surface of the facing that bonds the facing to the fibrous insulation blanket. The asphalt coating layer contains an odor-reducing additive in an amount to substantially eliminate odors that would otherwise be emitted by the asphalt coating layer. It is asserted that the additive does not adversely affect the adherent qualities of the asphalt coating layer. It is disclosed that the odor-reducing additive may be essential plant oils.
Conventional odor treating compositions commonly act as deodorizers or masking agents, essentially overwhelming the undesirable odor with one or more desirable odors. However, these compositions do not effectively mask the odors emitted from asphalt. Thus, there remains a need in the art for a composition that effectively reduces or eliminates the odors emitted from asphalt or other hydrocarbonaceous materials without simply masking the undesirable smell, where the performance of the composition is sustainable over time, and where the composition does not pose any additional health or safety issues.